A cobpoeation oe dela



Nov. 6 1923.

L. R. ROBERTS TYPEWRITER Filed Aug. 18 1921 2 Sheets-Sheet 1 Patented Nov. 6, 1823.

warren stares PATENT OFFICE.

LYMAN B. ROBERTS, OF BUTI-LERFORD, NEW JERSEY, ASSIGNOB TO L. B. ROBERTS TYPEW'BITER COMPANY, OF STAMFORD, CONNECTICUT, A CORPORATION OF DELA- WARE.

TYPEWRITER.

Application filed August 18, 1921. vSerial No, 493,340.

To all 10 from it may concern a citizen of the United States, residing at.

Rutherford, county of Bergen, and State of New Jersey, have invented certain new and useful Improvements in Typewriters, fully described and represented in the following specification and the accompanying drawings, forming a part of the same.

This invention relates to typewriters.

It is the principal object of the invention to provide a simple, effective and economical device for braking the movement of the carriage when it runs free, upon release of the escapement.

iVith this general object in view, the in vontion consists in the combinations, details of construction and arrangements of parts which will first be described in connection with the accompanying drawing and then more particularly pointed out.

In the drawing:

Figure 1 is a view in vertical cross-section of a portion of a typewriter constructed in accordance with the invention.

Figure 2 is a view of the same in rear elevation with parts broken away and removed.

Figure 3 is a sectional view showing parts in rear elevation, of the escapement mechanism.

Figure 4 is a sectional View, showing the same parts in side elevation, looking in the direction of the arrow in Fig. 3.

Figur 5 is a sectional view taken on the line 5-5 of Fig. 4.

Figure 6 is a sectional view taken through one end of the platen carriage.

Figur 7 is an edge view of one of the escapement dogs removed.

Figure 8 is a face view of the same, and Fig. 9 is a face view of the other escapement dog removed. I

The typewriter illustrated includes, in general, a frame, a carriage truck which may be movable relatively to the frame for case shift movement, and a platen carriage movable across the truck for printing. Referring to the drawings, there is provided a frame 11 illustrated more or less conventionally. At the rear corners of the frame are cylindrical bearing members 12 inwhich slide plungers l3. Mounted on these plungers to be moved thereby, as here illustrated as an example, is a carriage truck in the form of a rigid plate 14; The plungers 13, in the present embodiment, are connected below the bearings 12 by a cross rod 13 By means of this cross red the plungers may be raised to give case shift movement to the carriage truck. This may be accomplished by any uitable construction, for example, that shown in applicants copending application, Serial No. 263,116.

Th shaft 15 of the platen 16 is journaled in the end pieces 17 of a platen carriage 18. To mount the carriage for suitable printing movement, as here shown, two sets of ball bearings 19 ride in grooved rails 20 on the carriage and in a double grooved guide 21- supported from the truck plate 14 by two bracket arms 22. The carriage is driven through an escapement mechanism later described, power being derived from a spring drum 23 on the frame,having a cord 24 connected to one end of the carriage.

There is provided a set of key levers 28 only one being shown herein. In the present embodiment, each key lever 28 has a lug 40 located in a slot 39 in a hanger block 38. The lug, which is perforated, is pivoted on a wire 41 carried in a slot 42 also formed in the hanger 38. The key levers are connected with the type bars in any suitable manner.

Th action of the several key levers is transmitted to the carriage escapement by any suitable universal mechanism. As here shown as an example, the rear portions of the key lovers are raised against lugs 45 formed on a universal bar 46. The side arms 47 of this universal bar are secured to a universal rock shaft 48 journaled in the frame. I v

The carriage, normally drawn toward the left by the spring drum, is controlled by an escapement mechanism. While this escapement may vary in construction, in structures embodying the invention to the best advantage, it includes a fixed dog, a loose dog, an escapement wheel and a connection between the escapement wheel and the carriage, Although capable of various constructions, in that here shown as an example, associated with a dog carrier 49 is a fixed dog 50 which is conveniently formed as part of the carrier member. To move the fixed dog into and out of the plane of the escapement wheel later referred to, the carrier is pivotally mounted, by means of perforated lugs 51, on a pin 52 supported by the truck plate 1 The carrier 49 may be tilted by any suitable connection with the universal mechanism. is here shown as an example, th carrier has a depending portion 53 on which is lug 5% carrying a pin 55. This pin engaged by a rocker arm 56 mounted on the universal rock shaft 48.

Associated with the fixed dog is a loose dog which has a pivoted escapeiuent movement and a bodily movement for releasing the escapement. As here illustrated as an example, a loose dog 57 has a slot 58 through which passes a. pivot pin 59 carried by a lug 60 on the dog carrier e9. The loose dog is given its pivotal escapement movement by a spring (51 connected between a pin 62 on the loose dog and a pin 63 carried by the fixed dog.

.stbove the dog mechanism a star or cap ement wheelG-l which, in the present our bodiment. is rotatably mounted on a stud or pin 65 supported by a bracket (56 on. the truck plate To connect the star wheel with the carriage as here shown, connected to or integral with the wheel 6 is a pinion 67 meshing with rack 68 on the platen riage.

Normally the loose dog 57 is in the plane of the escape 'ient wheel 64: and engages a tooth thereof to hold the carriage. When the dog carrier is tilted by the universal mechanism the fixed dog moves in to engage said tooth the loose oog moving out. This permits the loose dog to move on its pivot (to the right in Figs. 3 and sutiiciontly to permit passage of a tooth of the escapeuient wheel. Upon return movement of the carrier 4.9, as the fixed dog moves out from the wheel the wheelcan move ahead one space until the next tooth engages the loose dog 5? which has meanwhile returned to the plane of the wheel. This movement of the cscapement wheel permits the carriage to move ahead one letter space. To control the pivotal movement of the loose dog justdcscribed, a bent leaf spring 69 is secured to the dog 57 and engages the pin 63 as the dog moves. 4

The invention inclinles means for releasing; the escapeinent to permit the carriage to run and in constructions having a dog meclv anism such as described, this is accomplished by moving the loose dog bodily downwards away from the escapement wheel. In con structions embodying the invention in its entirety. there is provided a tabulating mechanism including a key, and a connection between the tabulator key and the escapement release means. Although capable no sible is ma s a which the pivot pin o g e 5' in this movement tie body the dog is cut away as at to pro-- vid space tor the pin 63 and to form in effect a second slot and pin connection with c Upon release of the operating the loose dog 5'? returns to normal .OSltiOll under force of the spring 61. With 1. construction described. the same spring serves to return the loose dog after releasing movement and to move it ahead for escapeinent movement.

The tabulating mechanism includes, as here shown as an example a stop rack 77 on which are mounted any desired number of tabulating stops 'Z'S. Cooperating with these stops 78 is a stop 79 mounted on a movable stop carrier 80. This carrier is pi vo 'aly mounted by means of trunnions 8i journal'ed in bearings 82 carried by the truck 1%. To rock the carrier to place the stop 79 in line with the stops 78, the carrier has a ug 83 engaged. by a cam 84 mounted on the .ck shaft T l. To rock this shaft as here hown on the shaft is a rocker arm 85, conected by a link 86 with a tabulating key ever 87 having a key 88. This lever 87 is pivotally supported from the truck plate l l.

Normally, the stop 79 is out of line with the rack stop 78. lVhen, however, the tabulater hey is depressed. the shaft T l is rocked. This releases the escapcmcnt, as above described d also tilts the carrier to place the stop 79 in line with stops 78. As a result, the carriage runs until the stop To is engaged by he next stop 78.

Means is also provided for releasing the scapement a part from the tabulating mechanisni. As here shown as an example, pivoted to the end pieces 1'? of the carriage are the arms ot a release bail 90. One of these bail arns has a forked extension 91 which embraces a pin 92 on the short end of boll crank lever 93 pivotally mounted on a tie rod The other arm of: the bell crank terminates in a linger piece or handle 95. Below the release bail is an extension 96 formed on the lug '1'1 oil the loose dog 57. Operation of the handle 95 moves the bail 90 down against the lug extension 96 and "forces the dog 57 away from the escapement wheel, as before described. to permit the carriage to run. The throw of the bell crank and hence of the bail is limited by a stop lug 9? which engages a pin 98.

The invention includes a brake drum associated with the carriage to rotate as the 1 moves. lVhile the construction of b ke drum. will vary according to the renersl construction of the machine,'with the type oi carriage drive and escapement ere described, there is provided a brake drum in the form of a pulley member 92 secured to or formed integral with the escapement wheel 64 and pinion 67. Thus, when the carriage moves, the brake drum 92, pinion 76 and escapement wheel rotate as a unit.

Means is provided for applying a braking action to the brake drum upon release of the escapement mechanism. This may be accomplished, for example, by a resilient brake band which is tightened against the drum upon release of the escapement. Although capable of various constructions, in the present embodiment, a brake band is provided in the form of a coiled spring 93. One end Ark of this spring is fixed to a pin 94 on the bracket 66. The spring passes up over the drum 92 and down again, the other end being secured to a lug 95 on the rocker arm 73.

With the construction described, when the escapement is released by the tabulator key to permit the carriage to run, the movement of rocker arm 73 extends the spring brake band 93 and tightens it against the brake drum 92, thus effectively braking the carriage movement. Upon release of the tabulator key, the spring brake band is returned to its normal non-braking position by virtue of its inherent resiliency.

The invention includes means for controlling the braking action of the brake band. This may be accomplished, for example, by controlling the throw of the rocker arm 73. Although capable of various constructions, in the embodiment here illustrated, threaded through the truck plate 14 is an adjustable stop pin 99 which limits the throw of the tabulator key lever 87. By adjusting the position of this pin, the throw of the key lever 87, the rock shaft 74 and the rocker arm 73 is regulated and thus controls the tightening movement of the spring brake band 93. The pin 99 also serves a a guide for a return spring 100 for the tabulator key lever 87.

It is believed that the operation of such parts of a typewriter as are here involved will be clear from the foregoing without further description.

It is noted that with the typewriter described, there is provided an effective brake mechanism for braking tabulating movements, but movement of the carriage under hand release, i. e., by finger piece 95, is free from braking action.

What is claimed is:

1. In a typewriter, a platen carriage, in cans tending to drive the carriage, an escapement mechanism including an escapement wheel, a fixed dog and a loose dog, the loose dog being pivoted on a pin carried by the fixed dog and having a slot through which said pin passes, a brake drum rotating as the carriage moves, means for moving the loose dog bodily away from the escapement wheel to permit the carriage to run, and a brake band cooperating with said brake drum and having one end fixed and the other end connected with said dog moving means, whereby the brake band is tightened on the drum upon release of the escapement.

2. In a typewriter, a platen carriage, means tending to drive the carriage, escapement mechanism including an escapement wheel, a fixed dog and a loose dog, the loose dog being pivoted on a pin carried by the fixed dog and having a slot through which said pin passes, a brake drum arranged to rotate as the carriage moves, a tabulator key, a rock shaft, a connection between said tabulator key and the rock shaft, a rocker arm on the rock shaft, a contact portion on said loose dog for engagement by said rocker arm whereby the loose dog is moved bodily away from the escapement wheel upon operation of the tabulator key, and a brake band cooperating with said drum and having one end fixed and the other end connected with said rocker arm.

3. In a typewriter, a platen carriage, means tending to drive the carriage, an escapeinent mechanism including an esoapement wheel, a fixed dog. and a loose dog, the loose dog being pivotally mounted on a pin carried by the fixed dog and having a slot through which said pin passes, means for moving the loose dog bodily away from the escapement wheel to permit the carriage to run, spring means for giving the loose dog its escapement movement and returning it after release movement, and a pin carried by the fixed dog and serving as a stop for controlling the pivotal escapement movement of the loose dog and as a guide for the bodily release movement thereof.

4. In a typewriter, a platen carriage, means tending to drive the carriage, an escapement mechanism for the carriage, means for releasing the escapement mechanism to ermit the carria e to run a brake drum arranged to rotate as the carriage moves, a coiled spring serving as a brake band and cooperating with said drum, a connection between the brake band and the escapement releasing means, whereby the brake band is tightened on the drum upon release of the escapement, and means for regulating the braking 'actionof said brake band.

5. In a typewriter, a platen carriage, means tending to drive the carriage, an escapement mechanism for the carriage, a brake drum arranged to rotate as the carrizige moves, means including a rocker arm for releasing the escepement to permit the carriage to run, a coiled spring brake band cooperating with said drum and having one end fixed and the other end connected With said rocker arm, whereby the brake band is tightened upon the drum upon release of the escepement, and means for regulat 111g the throw of said rocker arni thereby to regulate the braking action of the brake 10 1 wand.

Intestimony whereof I have hereunto set 

